Mount Merapi (summit height 2,930 m asl, per 2010) is a volcano in the middle of Java Island and is one of the most active volcanoes in Indonesia. The southern slopes are in Sleman district administration, Yogyakarta Special Region, and the rest are in Central Java Province, Magelang regency on the west side, Boyolali regency on the north and east side, and Klaten regency on the southeast side. Forest areas around the peak of Mount Merapi National Park area since 2004.
This mountain is very dangerous because according to modern records eruption (peak liveliness) every two to five years and is surrounded by a very dense settlement. Since 1548, this mountain has erupted as many as 68 times. The city of Magelang and the city of Yogyakarta is the nearest major city, located under 30 km from its peak. On the slopes there are still settlements up to a height of 1700 m and only four kilometers from the summit. Because of this level of importance, Merapi is one of the sixteen volcanoes of the world included in the Decade Volcanoes project.
Geology
Mount Merapi is the youngest mountain in a series of volcanoes that lead south from Mount Ungaran. This mountain is formed due to activity in the Indo-Australian Plate subduction zone which moves down the Eurasian Plate causing the emergence of volcanic activity along the central part of Java Island. The current peak is not overgrown with vegetation due to high volcanic activity. This peak is growing on the southwest side of the peak of older Batulawang Mountain.
The process of formation of Mount Merapi has been studied and published since 1989 and beyond. Berthomier, a French scholar, divides the development of Merapi in four stages. The first stage is Pre-Merapi (up to 400,000 years ago), namely Mount Bibi whose parts can still be seen on the eastern side of the peak of Merapi. The Old Merapi Stage occurs when Merapi begins to take shape but not yet conical (60,000 - 8000 years ago). The remains of this stage are Bukit Turgo and Bukit Plawangan in the south, formed from basaltic lava. Next is the Medieval Merapi (8000 - 2000 years ago), characterized by the formation of high peaks, such as Gajahmungkur Hill and Batulawang, composed of andesite lava. The process of formation at this time is characterized by the flow of lava, lava breccia, and hot clouds. Merapi activity has been an effusive (melt) and explosive eruption. An explosive eruption is expected with the collapse of material to the west leaving the horseshoe morphology 7 km long, 1-2 km wide with several hills on the western slope. Pasarbubar Crater (or Pasarbubrah) is estimated to be formed at this time. The peak of Merapi now, Puncak Anyar, only began to form about 2000 years ago. In its development, it is known to occur several times explosive eruption with VEI 4 based on observation layer of tefra.
The characteristic of the eruption since 1953 is the insistence of lava to the top of the crater accompanied by the collapse of the lava dome periodically and the formation of hot clouds (nuée ardente) that can glide on the slopes of the mountain or vertically upward. This type of eruption of Merapi in general does not sound explosive sound but hiss. The summit dome that exists until 2010 is the result of a process that lasted since the 1969 gas eruption.
Geologists in 2006 detected a giant space under Merapi containing materials such as mud that "significantly inhibited earthquake vibration waves". Scientists estimate the material is magma. This magma sac is part of the formation formed by plunging the Indo-Australian Plate under the Eurasian Plate.
Peak of Merapi in 1930.
Small eruptions occur every 2-3 years, and larger ones are about 10-15 years old. Major eruptions of Merapi were recorded in 1006 (alleged), 1786, 1822, 1872, and 1930. The eruption in 1006 made the whole of the island of Java covered with ash, based on observations of volcanic ash deposits. Dutch geologist van Bemmelen theorized that the eruption caused the center of Medang Kingdom (Mataram Kuno) to move to East Java. The eruption in 1872 was considered the strongest eruption in modern geological records with the VEI scale reaching 3 to 4. The latest eruption, 2010, is also estimated to have near or equal forces. The 1930 eruption, which destroyed thirteen villages and killed 1400 people, was the eruption with the largest victims record to date.
The November 1994 eruption caused the hot clouds down to reach several villages and killed 60 people. The July 19, 1998 eruption was quite large but pointed upwards so it did not take any casualties. Note the last eruption of this mountain is in 2001-2003 in the form of high activity that goes on and on. In 2006 Merapi volcano back to high activity and had swallowed two lives volunteers in the area of Kaliadem due to exposure to hot clouds. The series of eruptions in October and November 2010 were evaluated as the largest since the 1872 eruption and claimed the lives of 273 people (as of 17 November 2010), despite intensive observations and refugee management preparations. The 2010 eruption was also observed as a deviation from the eruption of "Merapi type" because it is explosive accompanied by explosive sound and roar that sounded up to a distance of 20-30 km.
The mountain is monitored non-stop by the Gunung Merapi Observation Center in Yogyakarta City, assisted by various telemetry geophysical instruments around the mountain top as well as a number of visual observation and seismic checkpoints in Ngepos (Srumbung), Babadan and Kaliurang.
Eruption 2006
In April and May 2006, signs began to appear that Merapi would erupt again, marked by earthquakes and deformation. The local governments of Central Java and Yogyakarta have prepared evacuation efforts. Instruction has also been issued by both local governments so that residents who live near Merapi immediately evacuate to places that have been provided.
On May 15, 2006 Merapi finally erupted. Then on June 4, it was reported that the activity of Mount Merapi has surpassed the alert status. Head of BPPTK Daerah Istimewa Yogyakarta, Ratdomo Purbo explained that around 2-4 June the volume of lava in Merapi dome has reached 4 million cubic meters - meaning that lava has fulfilled the entire capacity of Merapi dome so that the latest lava burst will be directly out of the Merapi dome.
June 1, Volcanic ash rain from the glacial clouds of overcast Merapi volcano, the last three days occurred in Magelang and Magelang, Central Java. Muntilan about 14 kilometers from the peak of Merapi, most feel this ash rain.
On June 8, Mount Merapi at 09.03 WIB erupted with a blast of hot clouds that made thousands of people in the slopes of Mount Merapi panicked and tried to escape to safety. Today recorded two eruptions of Merapi, the second eruption occurred at around 09:40 pm. Hot clouds burst as far as 5 km further upstream Kali Gendol (southern slope) and burning part of forest area in the north of Kaliadem in Sleman regency.
Eruption 2010
The upgraded status of "normal active" to "alert" on September 20, 2010 was recommended by Balai Penyelidikan dan Pengembangan Teknologi Kegunungapian (BPPTK) Yogyakarta. After about a month, on 21 October the status changed to "standby" since at 18.00 pm. At this level of displacement activity has to be prepared. Due to the increasing activity, indicated by the high frequency of multiphase earthquake and volcanic earthquake, since 06.00 pm on 25 October BPPTK Yogyakarta recommends to increase the status of Mount Merapi to be "watch out" and all inhabitants of the region within 10 km radius from the peak must be evacuated and evacuated to the area secure.
The first eruption occurred at around 17:02 pm on 26 October. At least three eruptions occur. Eruption sprayed volcanic material as high as approximately 1.5 km and accompanied by the coming of hot clouds that hit Kaliadem, Desa Kepuharjo, District Cangkringan, Sleman. and killed 43 people, plus an infant from Magelang who died of respiratory problems.
Since then there began to be a vomit of hot clouds irregularly. Starting October 28, Merapi volcano spewed incandescent lava that appeared almost simultaneously with the release of hot clouds at 19:54 pm. Next observed the spot of silent fire at the peak on November 1, marking a new phase that the magma has reached the crater hole.
However, different from the usual Merapi character, instead of the formation of new lava dome, even that happens is increased activity of bursts of lava and hot clouds since 3 November. The explosive eruption of a large eruption began on the morning of Thursday, November 4, 2010, resulting in cloud columns as high as 4 km and bursts of hot clouds to various directions at the foot of Merapi. Furthermore, since about three o'clock during the day there was an incessant eruption until the evening and reached its peak in the early hours of Friday, November 5, 2010. By midnight, the radius of danger for all places zoomed to 20 km from the summit. This series of eruptions and roar sounds heard to the city of Yogyakarta (a distance of about 27 km from the peak), the city of Magelang, and the center of Wonosobo regency (50 km distance). Pebbles and sand reach the northern city of Yogyakarta, while the volcanic ash rain stretches to Purwokerto and Cilacap. By noon, volcanic ash is known to have reached Tasikmalaya, Bandung, and Bogor.
The secondary danger of cold lava flows also threatens the lower region after on 4 November there is heavy rain around the peak of Merapi. On November 5th, Code Times in the city of Yogyakarta was declared "alert" (red alert).
The powerful November 5 eruption was followed by high activity for about a week, before then a slight decrease in activity, but the security status remained "Watch out". On November 15, 2010 the radius hazard boundary for Magelang District was reduced to 15 km and for the other two Central Java districts to 10 km. Only for Kab. Sleman which still apply the radius of danger 20 km.
Vegetation
Mount Merapi at the top is never overgrown with vegetation due to its high activity. Types of plants at the top of the typical alpina type Java mountain ranges, such as Rhododendron and edeweis Java. Somewhat downwards there are bamboo forests and tropical mountain vegetation. The tropical rainforest of the mountains in the southern part of Merapi is one of the most rare endemic forms of endangered Vanda tricolor 'Merapi' orchids.
The slope of Merapi, especially below 1,000 m, is home to two national superior salak cultivars, namely 'Pondoh' and 'Nglumut' salak.
Climbing route
Mount Merapi is a popular climbing object. because this mountain is a very fascinating mountain. The most common and nearest climbing route is through the north side of Sèlo, Boyolali District, Central Java, precisely in Plalangan Village, Selo, Boyolali, This village is located between Mount Merapi and Mount Merbabu. Climbing through Selo takes about 4-5 hours to the top.
Another popular route is through Kaliurang, Pakem Sub-district, Sleman Regency, Yogyakarta on the south side. The line is more steep and takes about 6-7 hours to the top. Another alternative route is through the northwest side, starting from Sawangan, Magelang regency, Central Java and through the southeast side, from Deles direction, Kemalang sub-district, Klaten regency, Central Java.